The present invention is generally directed to gemstones and, more particularly, to non-round gemstones, preferably diamonds, having a unique cut that produces greater light amplification at the crown and table surfaces thereof.
The original round, brilliant-cut was developed by Marcel Tolkowsky in 1919. The round brilliant consists of 58 facets and is widely popular. In more recent years, non-round diamond shapes have come into vogue. The present invention is focused on non-round diamond cuts, such as those that are known as the emerald, cushion and radiant cuts. But the disclosure herein is also applicable to other oblong shapes, such as the marquis and oval cuts. It may even be applied to the asscher and princess cuts as well. The unique look of the emerald cut diamonds is created by the “step cuts” of its pavilion and its large, open table. Instead of the sparkle of the brilliant cut, emerald cut diamonds produce a hall-of-reflection-mirrors effect, with an interplay of light and dark planes. While less fiery, the long lines and dramatic flashes of light give the emerald cut an elegant appeal.
The present invention builds and improves upon the specially-shaped emerald diamond shown in the present inventor's issued U.S. Design Pat. No. D698,278, the contents of which are incorporated herein by reference.
As is well known, emerald and cushion cut diamonds have associated therewith certain parameters. These parameters include the crown angle, the crown height percentage, the girdle height percentage, the pavilion angle, the table percentage and the total depth percentage. Conventionally, the crown angle for an emerald cut is in the range of 35-36°. The pavilion angle is in the range of 40-41.5°. The total depth percentage is conventionally in the range of 60-70%.
As could be appreciated from the foregoing, emerald cut diamonds do not provide the brilliance and light reflecting experience which is the hallmark of the round, brilliant cut stones. The diamond trade has invested enormous efforts in searching for and attempting to find cuts that would increase the brilliance of oblong gemstones such as the emerald and cushion cut stones.